For the better part of three years, this writer has recommended an accelerated battle against Daesh (ISIS) in eastern Syria, one that would replace the pseudo-caliphate with a governance arrangement featuring reconstituted local councils, Syrian civil servants possessing needed skills, and the mainstream Syrian opposition – including the Turkish-supported Syrian Interim Government. Part of this recommendation is now being implemented. But the part that is not, may doom the enterprise. Ideally an administrative combination could be found for stabilizing eastern Syria that would enable the United States and its allies to recognize a new government for all of Syria, relieving Washington and others of recognizing a murderous criminal enterprise as a government entitled to a seat at the United Nations. Recognizing a new government would also help to address legal concerns pertaining to an ongoing American presence in Syria raised by Senator Tim Kaine and others.

That recommendation and nearly all others offered were rejected by an Obama administration ready to sacrifice Syrians (and the interests of allies in the region and Western Europe) under the mistaken impression that Tehran would have to be appeased in Syria to agree to a nuclear deal. The Trump administration did indeed accelerate the fight against Daesh, albeit by continuing to rely on a militia dominated by a Kurdish entity related to the terrorist PKK, instead of using a professional ground force coalition-of-the-willing: a situation understandably infuriating to a NATO ally (Turkey) that has suffered greatly from PKK terror.

The intent of the administration to keep Syria east of the Euphrates River out of the hands of a regime and Iranian-led militias whose presence would be catnip for Islamist extremists is laudable. But the methodology being applied may produce negative, unintended consequences.

In sum, the administration intends to use its anti-Daesh ground force combat component – the Kurdish-dominated Syrian Democratic Forces – to garrison Syria east of the Euphrates indefinitely and to serve as the basis of a 30,000-person border security force. The implication that this approach would require an ongoing American presence in eastern Syria was made explicit by Acting Assistant Secretary of State, David Satterfield, in recent Senate testimony. Four key actors – Russia, Iran, Turkey, and the Assad regime – have condemned the plan. To the extent they work in concert to defeat it, Washington may be in for a very rough ride.

Several months ago, this writer recommended that every effort be made to secure Turkey’s cooperation with (and involvement in) the post-Daesh stabilization of eastern Syria. This would have required a very heavy diplomatic lift, because the objective would have been daunting: to square the circle between neither abandoning a Syrian Kurdish “partner force” nor alienating a NATO ally which saw the dominating element of that force as the Syrian arm of the PKK. The Trump administration and Ankara know whether the United States made the maximum effort to involve Turkey and the Syrian opposition element Ankara supports – the Syrian Interim Government – in the post-Daesh governance of non-Kurdish parts of eastern Syria.

Even the heaviest and most sustained diplomatic lift by Washington might have fallen short. Many commentators on Turkish domestic politics suggest that President Recep Tayyip Erdogan, with his eyes firmly fixed on elections in 2019, has a vested interested in maintaining a high level of hostility – rhetorical and perhaps more – toward Kurdish adversaries to broaden his electoral appeal to Turkish nationalists. But if the strenuous effort was not made, then an opportunity to pay proper respect to a NATO ally – one that has provided important combat air facilities for the battle against Daesh – was missed.

What is missing from the eastern Syrian equation is any meaningful American outreach to a Syrian opposition that has faithfully adhered to the American-supported, United Nations-supervised Geneva peace process; an opposition that has demonstrated unceasing creativity in producing ideas ranging from using eastern Syria as a laboratory for the “transitional governing body” mandated by the 2012 Geneva Final Communique to ways and means of binding Syrian Kurds to a unitary Syria featuring empowered local governance for all. The failure to seek the assistance of the Syrian opposition in stabilizing lands liberated from Daesh is gratuitously self-damaging, and represents a straight-line continuation of failed Obama administration policy.

Still, the decision of the Trump administration to exclude the Assad regime and Iran from eastern Syria is sound. It is essential to sealing the victory over Daesh. To allow the area to be swallowed by Iranian-led militias and by a regime whose very existence inspires other forms of extremism would be to erase all the work that has been done to kill the false caliphate.

Has Ankara burned all the bridges leading to a possible accommodation with Washington on eastern Syria, one that would admittedly leave its Kurdish adversaries administering Kurdish parts of eastern Syria? Has Washington done all the requisite diplomatic due diligence to satisfy itself that there is simply no cooperative way forward with a NATO ally? Will the Trump administration continue, in effect, to leave money on the table by ignoring Syrian opposition elements capable of and willing to help stabilize eastern Syria?

The answers will help determine the success or failure of securing eastern Syria and promoting peace negotiations for the political transition all of Syria and its neighbors so desperately need. Surely the last thing Washington needs is a NATO ally working closely with Russia, Iran, and the Assad regime to undo a long campaign to defeat transnational terror and extremism in Syria east of the Euphrates River.

Frederic C. Hof is director of the Atlantic Council’s Rafik Hariri Center for the Middle East. This commentary is published by permission from the Atlantic Council and can be accessed at: http://www.atlanticcouncil.org/blogs/syriasource/securing-eastern-syria-in-2018. A version of this article appeared in the print edition of The Daily Star on January 25, 2018, on page 7.

The views and opinions of authors expressed herein do not necessarily state or reflect those of the Arab Network for the Study of Democracy